ATLANTA -- Dale Sveum had a blunt appraisal for the Cubs' play in the first half of the season and a simple plan for better results.
Sveum said the Cubs can improve by taking care of such basics as throwing strikes and hitting with runners in scoring position.
A few homers also help.
Maholm (6-6) gave up one run on eight hits in six innings. He had only one walk with five strikeouts.
The Cubs (31-50) are in last place in the NL Central but have won seven of their last nine and are only one-half game behind fifth-place Houston at the midpoint of the 162-game schedule.
"When you're 20 games under .500, you've obviously underachieved," Sveum said.
The Cubs have played like a contender against the Braves, winning two of the first three games in the four-game series after winning two of three in Chicago on May 7-9.
"Obviously, we've played some good games against them," Maholm said.
Maholm, a Mississippi native, said he enjoys pitching in Atlanta. He is 3-1 against the Braves in his career, including 2-0 this season.
"Obviously, I grew up a Braves fan," Maholm said. "I grew up watching Chipper (Jones) and (Tom) Glavine and (Greg) Maddux.
"It's hot and humid, what I grew up pitching in. I can't say I don't enjoy coming here."
The Braves, third in the NL East, fell 6 games behind first-place Washington.
"Sometimes, man, you meet a team that's playing good baseball," said Atlanta's Michael Bourn, who had three hits. "That's what's happening right now. (The Cubs) were earning it. Hey, we lost."
Rizzo's homer off Anthony Varvaro in the eighth was his second of the series and third overall since his recall from Triple-A Iowa on June 26.
Randall Delgado (4-9) allowed three runs on seven hits and two walks in six-plus innings. Delgado has lost four straight decisions.
Jones, who had five hits in the Braves' 10-3 win on Tuesday night, had a first-inning single to give him hits in six straight at-bats and a season-best 11-game hitting streak.
Jones added a sixth-inning single and advanced to second when Maholm hit Freddie Freeman with a pitch. With two outs, Jones was thrown out at the plate by left fielder Alfonso Soriano as he tried to score from second on a single by David Ross.
The Cubs scored in the first inning on a delayed double-steal. Starlin Castro, who walked, moved to third on Rizzo's single. Castro scored from third when Braves catcher David Ross threw Rizzo out trying to steal second.
Bourn tripled in the third and scored on Martin Prado's infield single.
LaHair's 14th homer in the fourth gave Chicago a 2-1 lead. The NL All-Star had two hits and a walk.
The Cubs added two runs in the seventh against Delgado and Jonny Venters. Darwin Barney doubled, moved to third on Luis Valbuena's groundout and scored on Delgado's wild pitch. Venters gave up a pinch-hit homer to Baker.
Venters has allowed six homers in 32 innings this season after giving up only three in 171 innings in 2010 and '11 combined. Venters' ERA is 4.45, and he no longer serves as closer Craig Kimbrel's primary setup man.
Braves manager Fredi Gonzalez said solving Venters' slump is crucial to the team's hopes for contending. Gonzalez said Venters doesn't have to be as dominant as he was in 2011, when he had six wins, nine saves and a 1.84 ERA.
"You feel like you have confidence in the young man," Gonzalez said.
"If we don't get him right -- and I'm not talking about last-year right -- we're going to be up against it."
Freeman almost tumbled into the Braves' dugout in the eighth as he leaned over the railing to catch Soriano's foul ball. Freeman's feet were in the air after he made the catch before his teammates stopped him from flipping.
Atlanta's Jason Heyward grimaced in apparent pain following a swing in the eighth inning. He remained in the game and said it was just a cramp.
"I can tell there's no strain," Heyward said.
Attendance was 40,604. ... Cubs RHP Ryan Dempster had his second bullpen session in three days and could come off the disabled list to start on Sunday against the Mets. Dempster has been on the 15-day DL since June 18 with tightness in his right lat muscle. ... The Braves released RHP D.J. Carrasco from Triple-A Gwinnett. Carrasco was signed to a minor league contract on June 20. ... Prado has a 10-game hitting streak. ... The four-game series ends Thursday with Atlanta's Mike Minor facing Chicago's Matt Garza.